Electrical contact actuator



Oct. 19, 1965 w. A. DE SMIDT ELECTRICAL CONTACT ACTUATOR 5 Sheets-Sheet1 Filed April 12 1962 T m M U E N m w E T vA T N l A 0 DH D O 5 a O 7 34 3 2 y 3 w m d 4 4M, 4I m 2 Q! 3 3 w T w e 4 5 7 I I 2 1 2 4 M My M. Z2

Oct. 19, 1965 w DE $M|DT 3,213,213

ELECTRICAL CONTACT ACTUATOR Filed April 12, 1962 3 Sheets-Sheet 2INVENTOR WOODROW A, DE SMIDT BY MM ATTORNEY Oct. 19, 1965 w, DE s3,213,213

ELECTRICAL CONTACT ACTUATOR Filed April 12, 1962 5 Sheets-Sheet 3INVENTOR WOODROW A. DE SMIDT ATTORNEY United States Patent 3,213,213ELECTRICAL CONTACT ACTUATOR Woodrow A. De Smidt, Whitefish Bay, Wis.,assignor to Allen-Bradley Company, Milwaukee, Wis., a corporation ofWisconsin Filed Apr. 12, 1962, Ser. No. 186,911 6 Claims. (Cl. 200-17)This invention relates to manually operated control units for openingand closing electrical contacts and the like, and it more specificallyresides in a watertight unit having a casing with a rear body portionfor insertion through a hole in a mounting panel and a forward headportion that will extend from such a panel, such casing containing aplunger that may be moved rearwardly for actuating associated switchcontacts, or the like, there also being a pivot shaft extendingtransversely through the head portion which enters the casing to engagethe plunger and which extends from the head to mount an operating lever,so that a manual depression of the lever pivots the shaft to actuate theplunger.

This invention primarily relates to manual control units for operatingelectrical contacts, which in turn momentari ly close or open circuitnetworks for the control and operation of power circuits. Such manualcontrol units are commonly referred to as push button units, and suchterm will be used occasionally herein to describe the present invention,although the embodiments described in the specification do not disclosethe usual form of button that is manually engaged. It will be observedthat a similar manual engagement, characterized by a pushing motion, isemployed in operating the embodiments described, so that the term pushbutton remains apropos. It is, in fact, an object of the invention toprovide a manually operated unit that preserves the push type ofoperation while incorporating a watertight construction not readilyobtainable by a unit having only a linear motion for its parts.

Commonly, electric motors for driving machines such as found inlaundries, creameries, tanneries, pump houses, outdoor installations andother areas where moisture is prevalent are connected across their powersources by means of electromagnetic switches that are enclosed in castiron, stainless steel, or aluminum cabinets with gaskets for the coversto render the enclosures watertight. The push button control units forenergizing and deenergizing the electromagnetic switches are similarlyencased in their own watertight cast iron, stainless steel, or aluminumenclosures, but at locations convenient to the operator. Such watertightenclosures are required to protect the electrical contacts frommoisture, and in many locations there is a likelihood that Water willregularly be sprayed against the device, so that moisture seepage is anacute problem. In dairies, for example, frequent application of Washwater around the equipment is necessary for sanitary reasons.

The conventional watertight push button assembly usually includes aspecial cover for the enclosure that has been carefully machined andfitted with some form of watertight seal. Also, generally, the enclosureis cast in a special form which is expensive and which requiressubstantial machining. There are, therefore, disadvantages in theconventional watertight push button which arise from the special natureof the watertight enclosures employed. Thus, a need has existed for sometype of selfcontained watertight push button which can be installed in astandard type of enclosure having a cover which is adapted to receiveand mount a watertight unit as well as other types of units.

Moreover, watertight push buttons must be able to withstand roughtreatment and exposure to the elements, and they must be able toadequately isolate the comparatively delicate electrical contactassembly and operating mechanism inside the enclosure from such externalconditions. These push buttons are used in a comparatively roughindustrial environment, and it is not unlikely that they will be jammedhome with a sharp blow from the heel of a hand, instead of beingcarefully depressed.

When such devices are used out-of-doors in a cold climate they are alsovulnerable to freezing and a conventional button construction can berendered completely unusable until the ice thaws. It must be anticipatedalso that an operator might seek to pound a frozen button loose with ahammer, or other tool, and the need of a durable construction isapparent. Accordingly, it is an object of this invention to provide awatertight manual control unit which can be installed in a simplifiedenclosure of a more usual construction and which is capable ofwithstanding abusive treatment.

It is another object of the present invention to provide a watertightcontrol unit assembly which is not rendered inoperative by icingconditions.

It is another object of this invention to provide a watertight controlunit assembly which has an improved, longer lasting, water seal.

It is another object of this invention to provide a watertight controlunit assembly which is lever operated.

It is another object of this invention to provide a watertight pushbutton type assembly which will completely isolate associated electricalcontacts from the rough treatment accorded such devices.

It is another object of this invention to provide a watertight controlunit assembly of an improved unitary construction in which the assemblydoes not include a cover as an integral part of the mechanism, as inprior devices in which operating shafts, for example, have beenjournaled in the covers themselves. Rather, in the present invention thecontrol unit is complete in an assembly separate from the cover and theassembly may be mounted in a plain cover that also is adapted for othertypes of push buttons, such as oiltight buttons and standard buttons. Asimple gasket between the cover and the assembly will afford aWatertight enclosure, and thus special manufacture for watertightconditions is minimized.

It is another object of this invention to provide a watertight controlunit that is also explosion-proof.

The foregoing and other objects will appear in the description tofollow. In the description, reference is made to the accompanyingdrawings which form a part hereof and in which there is shown by way ofillustration and not of limitation specific embodiments in which thisinvention may be practiced. These embodiments will be described insutficient detail to enable those skilled in the art to practice thisinvention, but it is to be understood that other embodiments of theinvention may be used and that structural changes may be made in theembodiments described without departing from the scope of the invention.Consequently, the following detailed description is not to be taken inlimiting sense; instead, the scope of the present invention is bestdefined by the appended claims.

In the drawings:

FIG. 1 is a view in perspective showing a control unit embodying theinvention as it appears when installed in an enclosure cover or amounting panel,

FIG. 2 is a side view in elevation of the control unit of FIG. 1 withparts broken away and in section to show interior construction,

FIG. 3 is a fragmentary view in side elevation of a portion of thecontrol unit with parts thereof moved into an operated position,

FIG. 4 is a plan view in partial section taken along the section line 44shown in FIG. 2,

FIG. 5 is a rear view in section without the enclosure 3 cover ormounting panel taken along the section line -5 shown in FIG. 4,

FIG. 6 is a view in section taken along the section line 66 shown inFIG. 2, and

FIG. 7 is a view in perspective of a plunger forming a part of thecontrol unit,

FIG. 8 is a front view in elevation of an alternative embodiment of theinvention with parts broken away to show underlying portions FIG. 9 is aside view in elevation of the embodiment shown in FIG. 8,

FIG. is a side view in elevation of the embodiment shown in FIG. 8 withthe operating lever in its depressed position and with parts broken awayto show underlying portions.

Referring now to the drawings, there is shown in FIG. 1 a manuallyoperable control unit having a casing 1 of die-cast construction and anelectrical contact assembly 2 which is mounted at the rear of thecasing 1. The casing 1 is preferably die-cast to provide a unitaryenclosure which will be watertight and which will exhibit requisitestrength, and to provide a desirable manufacturing medium for obtainingthe intricate configuration which is preferable for the casing 1. Thecasing 1 comprises a circular cylindrical rear body portion 3, that isthreaded about its exterior surface, and a forwardly projecting headportion 4. The body portion 3 is of reduced transverse dimension withrespect to the head portion 4, so as to be adapted for insertion throughan opening in an enclosure cover or a mounting panel, such as that whichis designated by the numeral 5.

By virtue of the greater transverse extent of the head portion 4 a flat,rearwardly facing shoulder 6 (see FIGS. 25) is formed at the juncture ofthe head portion 4 with the body portion 3. The shoulder 6 functions asa mounting surface for the casing 1 that extends circumferentially aboutthe forward end of the body portion 3, and it is formed with a groove 7which receives a gasket 8 that also completely encircles the bodyportion 3. The purpose of the gasket 8 is to form a watertight sealbetween the rearwardly facing shoulder 6 and the front surface of themounting panel 5 when the casing 1 is installed. For purposes ofinstallation the body portion 3 is preferably of circular cylindricalform and is threaded, as hereinbefore mentioned, to receive a ringshaped mounting collar 9. As seen in FIG. 1, the mounting collar 9 hasan outer surface which is knurled, so that it can be tightly grasped,and its inner surface is threaded correspondingly to the threads of thebody portion 3. Thus, to install the casing 1 in the mounting panel 5the body portion 3 is inserted through an appropriate hole in the panel5 from the front side until the rearwardly facing shoulder 6 of the headportion 4 abuts the front surface of the panel 5. The rear body portion3 of the easing 1 will protrude from the rear of the panel 5 and themounting collar 9 is then turned onto the body portion 3. The collar 9is drawn up tight against the inner surface of the panel 5 to pull therearward facing shoulder 6 with its gasket 8 tightly against the frontsurface of the panel 5 to form a watertight seal. This installation ofthe casing 1 is made before the electrical contact assembly 2 is securedto the after end of the casing 1.

Referring now more specifically to the head portion 4 of the casing 1,when it is viewed from the front the upper part thereof appears as abroad T. The cross piece of this T-shape comprises a downwardly andforwardly sloping surface 10 that receives a flush nameplate 11, as seenin FIG. 1, for displaying a use designation for the control unit. Theslope of the surface 10 enhances the shedding of water, and the surface10 extends transversely to each side to form a part of a pair ofprotective shields 12 that overhang the sides 13 of the head portion 4.

A vertical front surface 14 continues downward from the lower edge ofthe sloping surface 10 and gives the profile of the upper part of thehead 4 the shape of an outward jutting promontory that overhangs thelower part of head 4. The lower part of the head 4 is, in turn,characterized by a receded stop abutment 15 which is set well behind thefront surface 14. The front surface 14 also supports an eye 16 which isadapted to receive the shank of a padlock, such as shank 17 shown inFIG. 3, used for locking the mechanism of the control unit in a setposition.

A horizontal pivot shaft 18 extends transversely through the upper partof the head portion 4 with its end emerging from each of the side walls13 at locations directly beneath the protective shields 12. The headportion 4 is pro vided with an opening 19 that accommodates the shaft 18with a relatively close fit, and watertight seals in the form of O-rings20, as seen in FIGS. 4 and 5, are interposed between the shaft 18 andthe wall of the opening 19 by insertion in complementary groovesprovided in the shaft 18 at positions just inside the side walls 13.

A bail shaped operating lever 21 is fastened to the ends of the shaft 18by pinned connections so as to rotate in unison therewith. For theseconnections the operating lever 21 has a pair of vertically extendingside arms 22 which terminate at their upper ends in hubs 23 that receivethe shaft ends. The arms 22 are seen to extend alongside the sides 13and their lower ends merge with a horizontal bridging section 24 thatextends beneath the promontory-like upper parts of the head portion 4.

When the horizontal lever section 24 is in its normal, forwardmostposition, as seen in FIGS. 1 and 2, its front surface is insubstantially the same plane as the vertical surface 14. To actuate thecontrol unit being described the operator pushes the lever section 24rearwardly, very similarly as a push button is depressed with a linearmotion, and the lever 21 then swings about the pivot of the shaft 18, sothat the section 24 is moved toward the stop abutment 15. The stopabutment 15 will act as an arresting means for limiting the rearwardmotion of the lever 21, and the mid-portion of the section 24 willstrike the abutment 15 so that the operating force which is applied willbe directly transmitted to the more rugged mass of the head portion 4.In this manner any abusive, excessive forces will be absorbed by thecasing 1 to minimize damage that might otherwise occur to the lever 21.There is a direct line for the transmittal of the applied force from thefront of the lever section 24, through the section 24, and hence to theforward face of the abutment 15 which is at the same angle of slope asthe after face of the section 24 when the two parts are brought intoengagement. This direct line of force transmittal minimizes side thrustson the shaft 18 and accordingly promotes long life and maintenance of aclose watertight fit for the shaft 18.

The rear body portion 3 has a hollow interior in the form of a cavity 25which extends into the head portion 4 and communicates with the shaftopening 19, where by the central portion of the shaft 18 is exposedwithin the cavity 25. The cavity 25 is further characterized by alongitudinal rail or track 26 rising from the bottom of the cavity, andby a second rail or track 27 which depends from the upper wall of thecavity. Each rail 26, 27 extends for substantially the entirelongitudinal length of the cavity 25.

An H-shaped arm 28 is fastened to a flat on the pivot shaft 18 withinthe cavity 25, and it extends downwardly into the cavity 25 as shown inFIGS. 25. In order to utilize the full turning angle allowed by the sizeof the cavity 25 the mounting portion of the arm 28 is placed so as toface at a downward angle when the operating lever 21 is in its normalposition. Thus, when the pivot shaft 18 is rotated the arm 28 will pivotthereon in the cavity 25 without striking the cavity wall.

The arm 28 is a rigid plate, with notches 29 and 30 cut inward from itsupper and lower ends (see FIG. 5) to clear the tracks 26, 27 of thecavity 25. The arm 28 is also given a doglegged profile, as seen fromthe side, so

that it will present a vertical, rearward facing impelling surface 31 toa plunger 32 when the pivot shaft 18 is in its normal position.

The plunger 32, as is apparent in FIGS. 4 and 7, is a rectangular frameformed by a forward end 33, spaced side members 34, and an after end 35for engaging contact actuators 36 within the contact assembly 2 thatopen and close associated electrical control contacts (not shown). Theforward end 33 has feet 37 that extend toward the floor of the cavityand straddle the guide track 26 that extends upward from the floor ofthe cavity. This arrangement guides longitudinal movement of the plunger32 at its forward end. The forward end 33 of the plunger 32 also has acrown 38 at its top center which functions both as part of a spring seatand as a bearing surface to slide along the under side of the uppertrack 27 whenever the arm 28 forces the front of the plunger 32 upward.The after end 35 of the plunger 32 may be of any shape desired, and inthe preferred embodiment illustrated it is in the shape of a cross toaccommodate the particular contact assembly with which it is used.

A transverse cam surface 39 is formed across the forward end 33 of theplunger 32 by providing a downward and rearward slope for the forwardfaces of the feet 37. When the operating lever 21 is depressed, causingthe pivot shaft 18 to rotate, the impeller surface 31 of the arm 28moves rearward and upward against the transverse cam surface 39, with asliding pivot like motion which not only moves the plunger 32rearwardly, but slightly raises the front of the plunger 32 to avoid anypossible jamming or excessive wear with the rail 26. The sliding motionwith the surface 39 of the plunger 32 also moves the point of contactbetween the arm 28 and plunger 32 downwardly along the arm 28, so thatturning movement of a relatively short distance is converted into asubstantial amount of linear travel for the plunger 32.

A spring retainer 40 stamped from flat stock is secured to the after endof the track 26 and extends inside the open center of the frame shapedplunger 32 as seen in 'FIG. 6, the retainer 40 is a rectangular shapedplate having notches cut inward from its lateral edges to accommodatethe side members 34 of the plunger 32 to guide the plunger 32 as itmoves. A bias spring 41 is disposed in the opening formed in the centerof the frame shaped plunger 32 with its after end seated against thefixed spring retainer 40 and its forward end bearing against the frontpart 33 of the plunger 32. The spring 41 thus urges the plunger 32forward in the cavity 25.

To mount the contact assembly 2 a pair of diametrically oppositechannels 42 are cut in the outer, threaded surface of the rear bodyportion 3. The channels 42 are quite narrow and extend transverse of thebody portion 3. In addition, a pair of longitudinal grooves 43 are cutin from the after end of the body portion 3 to intersect with each ofthe channels 42. A C-shaped plate 44 has its ends inserted in thechannels 42 and its central part encircles about the exterior of thebody portion 3. A pair of mounting screws 45, which pass through thecontact assembly 2, extend through the grooves 43 and are threadedlyengaged with the ends of the plate 44. By drawing the screws 45 up tightthe parts are held assembled.

When the operating lever 21 is depressed it will rotate the pivot shaft18 and cause the arm 28 to push the plunger 32 rearward. The contactactuators 36 will then be moved, and in this operation the bias spring41 is compressed against the spring retainer 40. When the operatinglever 21 is released the bias spring 41 will expand and force theplunger 32 forward, thereby causing the pivot shaft 18 to rotate forreturning the operating lever 21 to its normal position. Movement inthis return direction is limited by the arm 28 striking the front wall46 of the cavity 25, and this also dictates the extent of the forwardtravel of the plunger 32.

The plunger 32 converts the limited circular movement of the arm 28,which in an actual embodiment may have a turning radius of less than aninch, to a substantial linear motion. For the example being given suchlinear motion was approximately one-half inch for satisfactory operationof the contact assembly. In this movement the transverse cam surface 39allows the arm 28 to slide along it as the arm 28 moves forward andupward through its arc. Since the arm 28 is normally vertical, thedirections of the forces it can impart to the transverse cam surface 39are rearward and upward. The slight upward force minimizes frictionalcontact between the plunger 32 and the track 26 so that wear is reducedand a wedging type movement with the track 26 is eliminated.

The interior working parts are fully housed within the rear body portion3 in comparative isolation from conditions exterior of the head portion4. Both abusive blows that may be struck against the control unit andhumid, wet conditions will not affect the working parts or theassociated electrical contacts operated by the unit. The physicalprotection of extending an operating lever beneath a promontory portionand to the front of an arresting abutment is coupled with desirablewatertight features in which the operating shaft is supported at spacedpoints so that tight seals for the shaft are maintained.

The alternative embodiment illustrated in FIGS. 8, 9 and 10 differs fromthe above described embodiment in the shape of its upper head portion 46and its operating lever 47. In the alternative embodiment, a broad roofportion 48 slopes gently downward from the mounting panel 66 until itmeets a narrower, more sharply downward sloping nameplate-bearingsurface 49. The nameplate bearing surface 49 terminates in a narrowvertical upper front surface 50, which extends the full width of theupper head portion 46, except for a deep notch 51 cutting through itscenter.

A horizontal bottom surface 52 extends from the lower edge of the upperfront surface rearwardly to join a lower front wall 53 at a pointapproximately below the junction of the roof portion 48 and thenameplate-bearing surface 49. The lower front wall 53 extends downward ashort distance to create a narrow vertical strip 54, with a centralgroove 63 cut in it in alignment with the notch 51 in the upper frontsurface 50. The lower front wall 53 angles rearwardly from the bottom ofthe vertical strip 54 to form a slanting portion 55 which merges withthe stop abutment 15. The roof portion 48 of the upper head portion 46forms protective shields 56 which overhang the ends of a horizontalpivotal shaft 65 protruding beyond the sides 13.

The operating lever 47 is cast in the form of a broad, horizontallyextending bridging section 57 suspended at its ends across the lowerfront wall 53, under and rearward of the upper front surface 50, bytriangular shaped side arms 58 extending front hubs 59, which areimmova-bly fastened around the protruding ends of the shaft 65. Thetriangular side arms 58 maybe visualized as having a rear side 60slanting forward and downward from the rear of each hub 59 to merge withthe bridging section 57 near its bottom edge, and a top side 61extending horizontally forward from the front side of each hub 59 to thetop of the bridging section 57. The bridging section 57 has a verticalfront face 62 extending downward from the top side 61 that is rounded atthe bottom to join with a rear side 62. A horizontally oriented eye 64to receive a padlock shank (not shown) entering from the side is formedon the center of the top edge of the bridging section 57 to fit in thenotch 51 in the center of the upper front surface 50 and the groove inthe lower front wall 53 when the operating lever 47 is in its normal,forwardmost position as shown in FIG. 9.

In addition to the above recited structural characteristics of theembodiment illustrated in FIGS. 8, 9 and 10, that embodiment is alsomodified so as to satisfy the standards for an explosion-proof pushbutton. The horizontal pivotal shaft 65 has a screw-thread fit in itsmounting in the head portion 46, with at least the minimum five threadsrequired for entering parts, although this mounting does not appear inthe drawings. The mounting panel 66 is of much heavier gauge than themounting panel shown in the previous embodiment, and the control unitmounting opening in it is threaded to permit the rear body portion 3 ofthe control unit to be screw-fitted therein. The C-shaped plate 67 isalso of heavier gauge than its counterpart (44) in the previousembodiment and a screw 68 is fitted through a threaded hole in it tobear against the inside surface 69 of the mounting panel 66 wedging thethreaded surface of the trunk portion 3 tightly in the mounting panel66.

Thus, the control unit of the present invention may be modified to beexplosion-proof as well as waterproof. The purpose of the threadedfittings is to provide a tortuous path for the expulsion of gases fromthe inside of the control unit and the enclosure. It is to be understoodthat the invention in either embodiment may be waterproof, orexplosion-proof, or both, as desired by employing the variousmodifications as described above.

The operating lever 47 of the alternative embodiment presents a muchlarger bridging section 57 than the corresponding operating lever 21 ofthe first embodiment. Similariy to the first embodiment, the operatinglever 47 of the alternative embodiment may be retained in its depressedposition by a padlock shank or other instrument inserted through the eye64. It should be noted that the bridging section 57 is substantiallyrecessed rearwardly of the vertical upper front surface 50, which can,therefore, present an abutment to moving objects which might otherwisedepress the operating lever 47 and a means for shedding water from theroof portion 48 and the nameplate-bearing surface 49 beyond the bridgingsection 57. Also, the broad bridging section 57 extending across thewhole lower front wall 52 presents a shield against water sprayedhorizontally against the front of the switch. When the operating lever47 is in its depressed position, the bridging section 57 abuts the stopabutment 15 which will receive any forces then exerted on the operatinglever 47, protecting the more delicate inner mechanisms of the pushbutton and switch described above.

I claim:

1. In a manually operated control unit the combination comprising: acasing having a rear body portion, a forward projecting head portionwith a rearwardly facing mounting surface to form a watertight unionwith a mounting panel and with a stop abutment formed beneath theforward projection thereof, and a longitudinal cavity extending througha substantial portion of its length; a pivot shaft extendingtransversely through said head portion and entering said cavity; sealingmeans between said shaft and said head portion; an operating leverjoined with and depending from said pivot shaft for swinging movementtherewith which has a transverse section disposed to the front of saidstop abutment and is engageable therewith for limiting its rearwardmotion; an

arm disposed in said cavity secured to said pivot shaft for forward andrearward movement within the cavity in response to turning of the shaft;a plunger mounted in said cavity, for longitudinal movement thereonwhich has a forward end adjacent said arm to be moved rearwardlythereby; a spring retainer secured at the after end of said body; and abias spring interposed between said plunger and said spring retainer andurging said plunger forward.

2. In a manually operated control unit the combination comprising: acasing having a hollow rear body portion open at its after end forinsertion in a mounting panel and a forward jutting head portion thatbroadens transversely from the rear portion to engage such a mountingpanel in a watertight seal; a rotatable shaft extending transverselythrough said head portion forming a watertight seal therewith and havingan arm extending within the hollow interior of Said rear body portion;an operating lever exterior of said head portion joined to said shaftfor rotating the same; a longitudinally movable plunger within saidhollow interior cooperatively engageable by said arm on said shaft to bemoved in response to shaft rotation; a mounting plate embracing theouter surface of said rear body portion of said casing and adapted toreceive mounting bolts; 21 contact assembly fastened across the afterend of said rear body portion by bolts secured to said mounting platewith a slidable contact member engaging said plunger; and a mountingmember adapted to engage the outer surface of said rear body portion andthe rear surface of said mounting panel to hold the control unit in saidmounting panel.

3. In a manually operated control unit the combination comprising: acasing having a hollow rear body portion open at its after end and aforward jutting head portion, said rear body portion having a raisedtrack extending longitudinally through its hollow interior; a rotatableshaft mounted by said head portion having an arm extending within saidhollow interior straddling said raised track to present a verticalimpelling surface when in its normal position and movable forwardly andrearwardly through a longitudinally extending arc; a longitudinallymovable plunger within said hollow interior having a curved cam surfaceextending transversely across its forward end to abut said arm and toform a surface across which said arm will move and slide as said arm ismoved in said hollow interior imparting motion to said plunger; and acontact assembly mounted across the after end of said casing and havinga slidable member engaging the after end of said plunger to open andclose contacts when said plunger is moved.

4. In a manually operated control unit the combination comprising: acasing having a hollow rear body portion open at its after end and aforwardly jutting head portion, said rear body portion having a raisedtrack extending longitudinally through its hollow interior; a rotatableshaft mounted by said head portion having an arm extending within saidhollow interior movable forwardly and rearwardly through alongitudinally extending arc; an operating lever exterior of said headportion joined to said shaft for rotating the same; a longitudinallymovable plunger within said hollow interior having a four sided openframe comprised of laterally spaced side members, a front membercrossing over said track and a rear member that presents a rearwardlyfacing working surface movable from the rear body portion upon rearwardmove ment of the plunger, said plunger having feet on each side of saidtrack to straddle the same and further having a front face disposed inthe arc of said arm to be struck thereby; a spring seat extendingthrough the open frame of the plunger at the rear of the frame; and abias spring inserted in said open frame bearing at one end against thespring seat and its other end against the front member of the frame.

5. In a manually operated control unit the combination comprising: acasing having a rear body portion for insertion in a mounting panel anda forward jutting head portion that broadens transversely from the rearportion to present a mounting surface, said head portion having apromontory-like upper part and a stop abutment beneath and setback fromthe forward extremity of the upper part; a rotable shaft extendingtransversely through said upper part of said head portion and protrudingfrom the sides thereof; an operating lever having depending arms thatare attached to the ends of said shaft and which extend alongside thesides of the head portion, and having a transverse section bridgingbetween said arms which crosses the front of said abutment and isdisposed beneath said promontory-like upper part of said head portion,whereby a rearward depression of said transverse section moves the sametoward the abutment and pivots said shaft; means connected with saidshaft for transmitting a rotary motion of said shaft in a substantiallyrectilinear direction; and a plunger within said rear body portion ofsaid casing cooperatively engageable with said means to be movedsubstantially rectilinearly in response to shaft rotation.

6. In a manually operated actuator for electrical contacts, thecombination comprising: a casing having a rear body portion forinsertion in a mounting panel and a forward jutting head portion thatbroadens transversely from the rear body portion to present a mountingsurface; a rotatable shaft journaled transversely through said headportion and having at least one end protruding from the sides thereof;an operating lever having at least one depending arm that is attached atone end to the protruding end of said shaft, whereby a rearwarddepression of an end of said operating lever remote from said shaftpivots said shaft; means connected with said shaft for transmitting arotary motion of said shaft in a substantially rectilinear direction;and a plunger within said rear body portion of said casing cooperativelyengageable with said means to be moved substantially rectilinearly inresponse to shaft rotation.

References Cited by the Examiner UNITED STATES PATENTS 1,693,126 11/28Van Ryan et a1 200-42 2,521,519 9/50 Hunter et al. ZOO-16 2,740,023 3/56Kryder 200-168 2,943,162 6/60 Norden 200-42 X 2,984,726 5/61 Roeser200-168 3,047,682 7/62 Hults ZOO-16 3,081,390 3/63 Lasar 20042 X3,104,120 9/63 Myers 285161 BERNARD A. GILHEANY, Primary Examiner.

6. IN A MANUALLY OPERATED ACTUATOR FOR ELECTRICAL CONTACTS, THECOMBINATION COMPRISING: A CASING HAVING A REAR BODY PORTION FORINSERTION IN A MOUNTING PANEL AND A FORWARD JUTTING HEAD PORTION THATBROADENS TRANSVERSELY FROM THE REAR BODY PORTION TO PRESENT A MOUNTINGSURFACE; A ROTATABLE SHAFT JOURNALED TRANSVERSELY THROUGH SAID HEADPORTION AND HAVING AT LEAST ONE END PROTRUDING FROM THE SIDES THEREOF;AN OPERATING LEVER HAVING AT LEAST ONE DEPENDING ARM THAT IS ATTACHED ATONE END TO THE PROTRUDING END OF SAID SHAFT, WHEREBY A REARWARDDEPRESSION OF AN END OF SAID OPERATING LEVER REMOTE FROM SAID SHAFTPIVOTS SAID SHAFT; MEANS CONNECTED WITH SAID SHAFT FOR TRANSMITTING AROTARY MOTION OF SAID SHAFT IN A SUBSTANTIALLY RECTLINEAR DIRECTION; ANDA PLUNGER WITHIN SAID REAR BODY PORTION OF SAID CASING COOPERATIVELYENGAGEABLE WITH SAID MEANS TO BE MOVED SUBSTANTIALLY RECTILINEARLY INRESPONSE TO SHAFT ROTATION.